Herbicidally active substituted phenyl carbamates
in which R' represents a C1-C6 alkyl group, a C3-C8 cycloalkyl group or an aryl group, which aryl group may be substituted by a halogen atom and/or a C1-C6 alkyl group and/or a trifluoromethyl group, and R2 represents a C1-C6 alkyl, C2-C6 alkenyl or C2-C6 alkynyl group that may be substituted by a terminal halogen atom, are prepared by reacting N-hydroxyphenyl carbamates II
with either isocyanates R'-N=C=O or amino acid chlorides R'-NH-COCI in an aqueous medium thus avoiding the use of organic solvents. The end product I may be extracted from the aqueous slurry into a water-immiscible solvent.
The N-hydroxyphenyl carbamates II can be prepared by reacting 3-aminophenol with chloroformates in an aqueous medium, and the resulting product may be reacted in situ, without isolation, with isocyanates, in the same reaction vessel.
Stabilized herbicidal compositions containing compounds I may be prepared by suspending the compounds I in a liquid phase comprising one or more oily components and one or more surfactants.
具有除草活性的取代苯基
氨基甲
酸酯类化合物
其中 R'代表 C1-C6 烷基、C3-C8 环烷基或芳基,该芳基可被卤素原子和/或 C1-C6 烷基和/或三
氟甲基取代,R2 代表可被末端卤素原子取代的 C1-C6 烷基、C2-C6 烯基或 C2-C6 烷炔基,通过使 N-羟基
苯基氨基甲酸酯 II 与
异氰酸酯 R'-N=C=O 或
氨基酸氯化物 R'-NH-COCI 反应制备。
与
异氰酸酯 R'-N=C=O 或
氨基酸氯化物 R'-NH-COCI 在
水介质中反应,从而避免使用有机溶剂。最终产品 I 可从
水性浆液中提取到
水不溶性溶剂中。
N-hydroxyphenyl carbamates II 可通过在
水介质中使 3-aminophenol 与
氯甲酸酯反应来制备,所得产物可在同一反应容器中与
异氰酸酯原位反应,无需分离。
含有化合物 I 的稳定除草组合物可以通过将化合物 I 悬浮在包含一种或多种油性成分和一种或多种表面活性剂的液相中来制备。